Crown shyness (also canopy disengagement) is a phenomenon observed in some tree species, in which the crowns of fully stocked trees do not touch each other, forming a canopy with channel-like gaps. The phenomenon is most prevalent among trees of the same species, but also occurs between trees of different species. There exist many hypotheses as to why crown shyness is an adaptive behavior, and the most prominent theory, is that the gaps prevent the proliferation of invasive insects.
By Patrice78500 – Own work, Public Domain, Link
The phenomenon has been discussed in scientific literature since the 1920s. The variety of hypotheses and experimental results might suggest that there are multiple mechanisms across different species. Some hypotheses contend that trees in windy areas suffer physical damage as they collide with each other during winds. As the result of abrasions and collisions, there is an induced crown shyness response. However a Malaysian scholar who studied Dryobalanops aromatica, found no evidence of abrasions due to contact in that tree. He suggested that the growing tips were sensitive to light levels and stopped growing when nearing the adjacent foliage due to the induced shade.
Photo: Dag Peak
By Mikenorton – Own work, CC BY-SA 3.0, Link
7 thoughts on “Crown Shyness – A Phenomenon Where Trees Avoid Touching”
Reblogged this on New Perspectives 101.
I have never heard of crown shyness. Love the tree images. It seems like there should be a logical explanation for this occurrence. One would think there would be a lot of research on this.
Immagini speciali, come sempre
I like it 😊
Wow…how interesting. Thank you.
I’ve noticed something that might be this in California Oaks; I will now go back and look closer! IN any event, the pictures are dramatic! How did you come across this?
Nature is so cool!